Starter gearing



June 1, 19 3- s. A. STAEGE 1 STARTER GEARING Filed June 26, 1940 Patented June 1, 1943 STARTER GEARING Stephen A. Staege, HamiltonuOhio, assignor to The Black-Clawson Company, Hamilton, Ohio, a corporation of Ohio Application June 26, 1940, Serial No. 342,598

4 Claims.

This invention relates to starting devices for starting paper machinery rolls and the like.

One object of the invention is the provision of a drive and starting device for paper machinery rolls, embodying a prime mover having a clutch by means of which it is placed in driving connection with the rolls, and an electric starting motor or rolls having an automatically shiftable pinion which is moved into mesh with a gear connected to the rolls when the starting motor is started and which is automatically moved out of mesh with the gear when the prime mover is clutched to the rolls and drives the rolls atan increased speed.

Another object is the provision of a starting device for paper machinery rolls, embodying an electric starting motor having a threaded shaft carrying a pinion which is automatically movable in an axial direction along the shaft into mesh with the roll driving gear when the starting motor is started and axially movable out of me'sh by the gear when the latter is driven from a main drive under normal operating conditions, there being provision for controlling the position of the pinion along the shaft to insure proper automatic action of the pinion and prevent the pinion from being moved inadvertently into mesh with the gear if 'the starting motor remains in operation after the main drive has been connected to the load.

Another object is the provision of drive and starting mechanism embodying a main drive adapted to be connected to the load, and an electric starting motor having a pinion which is automatically movable into and out of mesh with a gear connected to the load, the construction being such as to provide satisfactory and reliable operation so as to disconnect the starting motor automatically and prevent the starting pinion from again engaging the load until the starting motor is stopped and then started again.

Other objects and advantages of the invention will be apparent from the following description, the appended claims and the accompanying drawi In the drawing,

Fig. 1 is a side elevation of the drive and starting mechanism embodying the present invention;

Fig. 2 is a top plan view of the drive and starting mechanism;

Fig. 3 is a vertical sectionon the line 3-3 of Fig. 2, on an enlarged scale;

Fig. 4 is a section on the line 4-4 of Fig. 2; and

Fig. 5 is a plan view of a series of drier rolls .of a paper making machine, in which the drive and starting mechanism is incorporated.

The drawing shows the preferred embodiment of the invention as a drive and starting mechanism for starting a series of paper machinery rolls such .as the drier rolls or other paper carrying rolls of a papermaking machine, at a compai'atively slow speed, and providing for operation of the rolls at increased speed under normal conditions with the starting motor disconnectedv Referring more particularly to the drawing by reference numerals, the same reference numerals being used to'designate like parts in the several views, ill designates a gear, which is connected to a load which, in the embodiment of the invention shown, is a series of paper drier rolls ll of a drier section. These rolls are rotatably carried on the machine frame 12. The gear I0 is fixed on a shaft l3 which is rotatably mounted in a bearing [4, the latterbeing mounted on or forming a partof the frame iii of the drive and starting mechanism.

The rolls I I, of the drier section, under normal operating conditions, are driven from a main drive which also operates other drier roll sections, calender rolls, etc. As shown, this main drive comprises a prime mover I6, preferably an electric motor, operating a line shaft having a pulley wheel I! which is connected by belt Hi to the pulley wheel 19 rotatably mounted on the shaft 13.

The pulley wheel I9 is adapted to be placed in driving connection with the shaft I3 by means of a suitable clutch 20 under the manual control of the operator. The driven hub portion 2| of the clutch, which is keyed to the shaft 13, may be moved by shifting the clutch control lever 22, the clutch preferably being of the character disclosed in the prior patent of Herman L. Kutter No. 1,949,053, dated February 27, 1934. When the pulley wheel I9 is placed in driving connection with the shaft Hi, the rolls H are operated at their normal speed of rotation, through bevel pinion 23, bevel gear 24, shaft 25 and gear 26 which meshes with and operates the gear train 21 with which the rolls II are provided. The rolls will thus be operated in suitable timed relation.

After the rolls have been brought up to speed, the amount of power transmitted through the normal power drive is not excessive, and imposes no undue strain on the driving parts, but an unusually large torque is required to start the rolls from a position of rest, since the static friction of the bearings of the rolls is quite high, and to overcome the. static friction of plane bearings at a time when the rolls are stationary may require a torque as much as ten times as high as that required for the running friction, so high in fact as to impose a great strain and produce an unusually large amount of wear on the friction plates of the clutch. It may also be desirable to operate a roll section of a paper making machine at very low speeds for purposes of observation or repair. In accordance with the present invention, therefore, an electric motor of comparatively small power but of high starting torque as compared with the prime mover is provided for starting purposes so that the load can be started from a position of rest, and driven at a comparatively slow rate of speed, say about several per cent of the normal running speed, before the driving force from the main drive is applied to the load. This starting motor is provided with an automatically shiftable pinion that moves into mesh with the gear connected to the load, when the starting motor is started, and automatically moves out of mesh with that gear when the prime mover operates the load at in creased speed. When the starting motor operates the load, the rolls may be inched along, when occasion requires, to give successive limited amounts of movement preparatory to actual starting, by suitable control of the starting switch of the starting motor, or the starting motor may remain connected to the load to move the load at comparatively slow speed until such time as it is desired to connect the main drive to the load. After the main drive is connected, the starting motor will be automatically disconnected, and the operator, at any time after its disconnection, may deenergize the starting motor.

The starting motor, shown at 28 in the drawing, is a small electric motor mounted on the ed for axial movement along, the shaft to an inner position in which the side of the pinion engages a boss 34 on the shaft and the pinion is in meshing engagement with the gear ID from an outer position in which the pinion is spaced some little distance away from the gear. The threads are steep enough so that the pinion will not lock against the boss 34. Fixed to the pinion 33 is an inertia plate 35, these parts being secured together by means of screws 36. The inertia plate, which is of greater diameter than the pinion, tends to hold the pinion against rotation temporarily, when the shaft 33 first starts to rotate, and the pinion is thus made to travel axially along the shaft towards the right as viewed in Fig. 3 from the position shown, bringing the pinion into mesh with the gear l8 so that the load will then be started and slowly rotated by the starting motor I8.

After the load has been started, the prime mover is connected to the rolls by operating the clutch 28, and this increases the speed of rotation of the gear l8 without producing a corresponding increase in the speed of the shaft 38, so thatthe pinion will be moved axially outwardly along the shaft 38 out of mesh with the gear I8, turning rapidly enough on the shaft so that it will be thrown out until the outer side of the inertia disk comes up against a friction member 38 which is carried by an arm 38. The arm holds the friction member against rotation and locates it in such position that when the pinion inertia disk engages it, the pinion will be spaced some little distance away from the gear l8. As soon as the rapidly rotating pinion is brought up against the friction member 38, the speed of the pinion is temporarily reduced below the speed of rotation of the shaft 38 by reason of the rubbing engagement of the inertia disk with the friction member, the result being that the pinion is screwed back along the shaft towards the gear 18 until it is completely free from the friction member 38 and it then stops its axial movement while still some distance away from the gear ID. If the starting motor is still running, the pinion and the shaft 38 will rotate at the same speed, without producing any relative axial movement of the pinion along the shaft, and there would be no tendency for the pinion to be brought into mesh again with the gear I8 with the main drive connected. The operator, however, disconnects the switch that energizes the starting motor 28, after the main drive has brought the load up to speed.

Pivotally carried by the inertia disk 35 are friction arms 48 and 4|, mounted on pivot studs 42 and 43 and free to move on those studs, which are parallel to the axis of the shaft 38. The

lower ends of these arms are yieldingly interconnected to one another by means of a stud 44 threaded in an outwardly projecting fiange'45 on the arm 48, and a spring 46 which engages the head of this stud and also engages a flange 41 on the arm 4|. The spring 46. the tension of which can be readily adjusted by operating the screw 44, thus holds the friction brake surfaces 48 and 49 of these arms against the outer sides of the screw threads on the shaft 38, and provides a comparatively small but substantially constant and continuous frictional connection between the pinion and the shaft so that the pinion tends to rotate at the same speed as the shaft. The frictional connection between the pinion and the shaft however is such as to permit axial movement of the pinion along theshaft 38 when that shaft is first started and the pinion is at rest, before the pinion approaches the speed of the shaft, so that sufiicient axial travel of the pinion towards the gear I8 takes place and the .pinion is brought into mesh with the gear/l8 every time the starting motor is first started.

The frictional engagement between the arms 48 and 4| and the threads on the shaft is such as to' permit only a small axial travel of the pinion along the shaft in the direction of the gear in after the pinion engages the friction member 38 following energization of the main motor.

As will now be apparent the rolls of the paper making machine may be started without imposing great strains or causing undue wear in the clutch which serves to connect the main drive,

and the rolls may be operated at a slow rate of speed for as long as desired, or may be inched along as occasion may require. The inertia and static friction having been overcome by the starting motor, the main drive is then connected and the disengagement of the starting motor is automatically accomplished. The starting pinion, when freed of the gear, assumes a position on the starting motor shaft in which it is mechanically isolated from any holding friction and from the gear, and it will maintain this position during the continued energization of the starting motor and until the starting motor is stopped. The starting motor may then be deenergized and stopped by the operator at any time, and if this is not done promptly after the main drive is connected it will merely result in a small power consumption, as the continued operation of the starting motor will not cause reengagement of the pinion 33 and the gear In. The construction is such that an appreciable movement of the pinion 33 takes place to mesh with gear l0, when the starting motor is energized, despite variations in temperature, humidity, or other variable factors.

While the form of apparatus herein described constitutes a preferred embodiment of the invention, it is to be understood that the invention is not limited to this precise form of apparatus, and that changes may be made therein without departing from the scope of the invention which is defined in the appended claims.

What is claimed is:

1. Starting mechanism of the character described comprising a rotatable gear adapted for power operation at comparatively high speed, an electric starting motor having a threaded shaft extending parallel with the gear axis, a pinion threaded on the shaft and automatically movable in an axial direction along the shaft into mesh with said gear when the starting motor is started and axially movable out of mesh when the gear is operated at high speed, a substantially stationary friction member facing towards a side of said pinion, means preventing rotation of said member about the pinion axis and supporting the member in a definite predetermined position so spaced from the gear as to be abutted by the pinion only after a substantial axial travel of the pinion following its disengagement from said gear, said member acting to temporarily reduce the speed of pinion rotation to a point below that of the shaft to cause return of the pinion a short distance toward the gear and free of the gear and the member, and means providing an adjustable friction connection directly between the pinion and the threaded shaft.

2. Starting mechanism of the character described comprising a rotatable gear adapted for power operation at comparatively high speed, an electric starting motor having a threaded shaft extending parallel with the gear axis, a pinion threaded on the shaft and automatically movable in an axial direction along the shaft into mesh with said gear when the starting motor is started and axially movable out of mesh by the gear when the gear operates at increased speed, a friction member facing towards said pinion, means preventing rotation of said member about the pinion axis and supporting the member in a temporarily reduce the speed of pinion rotation to a point below that of the shaft to cause return of the pinion a short distance toward the gear and free of the gear and the member, and

adjustable means pivotally carried by said pinion and in frictional engagement with said shaft and providing a substantially constant frictional connection between the pinion and the shaft.

3. In a drive and starting mechanism, 'an electric starting motor having a threaded shaft. a pinion assembly threaded on the shaft and movable axially into and out of engagement with a gear to be started and to be subsequently rapidly operated independently of the starting motor, a stationary friction member positioned to be abutted by the pinion assembly only after its complete release from the gear caused by rapid rotation of the gear, and an adjustable friction connection between the pinion assembly and the threaded shaft such that the pinion assembly after being thrown out of mesh with the gear attains a position on the shaft in which it is mechanically isolated from everything except the shaft and in which it is maintained during continued operation of the starting motor and during the deenergization period of the starting motor.

4. Starting mechanism of the character described for a driven element comprising a drive jelement adapted for driving engagement with I said driven element, a threaded shaft on which said driven element is mounted and over which it moves in a direction toward engagement with said driven element in response to rotation of said shaft faster than said element and in the opposite direction to a limiting position when rotated faster than said shaft, said driving element having a free floating position intermediate said engaged position and said limiting position where it is isolated except for its contact with the shaft, said drive element having sufficient inertia to be moved from said intermediate position to said drive position upon starting of said drive member, means in said limiting position for checking rotation of said element in excess of the rate of rotation of said shaft to cause return travel of said dri e element to said intermediate position to r tate in that position at the same speed as the shaft and without travel thereon, and means for controlling the frictional engagement between said driving element and said shaft. STEPHEN A. STAEGE. 

